Keyswitch

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a keyswitch, and more specifically, to a keyswitch utilizing a support mechanism located between a first support plate and a second support plate to be movably connected to a cap and a base plate for increasing a pull-out force of the cap.

2. Description of the Prior Art

A keyboard, which is the most common input device, can be found in variety of electronic apparatuses for users to input characters, symbols, numerals and so on. Furthermore, consumer electronic products and industrial machine tools are all equipped with a keyboard for performing input operations.

A stroke of a cap of a conventional keyswitch is relatively long, so it is easy to dispose a rubber dome under the cap so that when the cap is pressed to move downward, the rubber dome is deformed and produces resilient force, and when the cap is released, the resilient force drives the cap to move upward to its original position. However, with a tendency toward keyboard miniaturization, the stroke of the cap is required to decrease, so the height of the rubber dome is also required to decrease. The service life and the resilient force of the keyswitch decays with a decreasing height of the rubber dome. Furthermore, for a keyswitch with a longer length (or called a multiple-width keyswitch), a plurality of links is disposed under the cap so that the cap can remain horizontally while being moved up and down by a user pressing any portion of the cap, and the user can feel a distinct force feedback (or tactile feedback). However, if the height of the cap is required to decrease more, the aforesaid design may not be accomplished easily due to space constraint. Moreover, the aforesaid link connection design can also reduce the pull-out force of the cap to cause the problem that the cap could fall off easily.

SUMMARY OF THE INVENTION

The present invention provides a keyswitch. The keyswitch includes a base plate, a cap, a lifting mechanism, a returning device, and at least one support mechanism. The cap has a longitudinal axis. The lifting mechanism is disposed between the base plate and the cap. The cap is movable between a pressed position and a non-pressed position relative to the base plate via the lifting mechanism. The lifting mechanism includes a first support plate and a second support plate coupled to each other. The first support plate has at least one first opening. The base plate is partially disposed through the at least one first opening to make the first support plate movably connected to the base plate. The first support plate has a first edge and a second edge. The first edge abuts against the base plate. The second edge is opposite to the first edge and abuts against the cap. The first edge and the second edge are parallel to the longitudinal axis. The second support plate has at least one second opening. The base plate is partially disposed through the at least one second opening to make the second support plate movably connected to the base plate. The second support plate has a third edge and a fourth edge. The third edge abuts against the base plate. The fourth edge is opposite to the third edge and abuts against the cap. The third edge and the fourth edge are parallel to the longitudinal axis. The returning device is located between the first support plate and the second support plate for providing a returning force to drive the cap to move from the pressed position back to the non-pressed position with rotation of the first support plate relative to the base plate via the first edge and rotation of the second support plate relative to the base plate via the third edge. The at least one support mechanism is located between the first support plate and the second support plate. The at least one support mechanism has a first support member and a second support member. The first support member is movably connected to the cap and the base plate. The second support member is movably connected to the cap and the base plate and is pivoted to the first support member.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> is a diagram of a keyswitch according to an embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 2</figref> is a cross-sectional diagram of the keyswitch in <figref idref="DRAWINGS">FIG. 1</figref> along a cross-sectional line A-A.

<figref idref="DRAWINGS">FIG. 3</figref> is a cross-sectional diagram of a cap in <figref idref="DRAWINGS">FIG. 2</figref> being pressed to a pressed position.

<figref idref="DRAWINGS">FIG. 4</figref> is an enlarged diagram of a first support plate and a second support plate in <figref idref="DRAWINGS">FIG. 1</figref> from another viewing angle.

<figref idref="DRAWINGS">FIG. 5</figref> is an exploded diagram of a base plate, the cap, and a support mechanism in <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 6</figref> is a partial enlarged exploded diagram of the keyswitch in <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 7</figref> is a diagram of a keyswitch according to another embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 8</figref> is a cross-sectional diagram of the keyswitch in <figref idref="DRAWINGS">FIG. 7</figref> along a cross-sectional line B-B when the cap is pressed.

<figref idref="DRAWINGS">FIG. 9</figref> is an assembly diagram of the cap, the first support plate and the second support plate according to another embodiment of the present invention.

DETAILED DESCRIPTION

Please refer to <figref idref="DRAWINGS">FIG. 1</figref>, which is a diagram of a keyswitch <b>10</b> according to an embodiment of the present invention. For clearly showing the internal mechanical design of the keyswitch <b>10</b>, a cap <b>14</b> is depicted by dotted lines in <figref idref="DRAWINGS">FIG. 1</figref>. As shown in <figref idref="DRAWINGS">FIG. 1</figref>, the keyswitch <b>10</b> could preferably be a keyswitch with a longer length (also called a multiple-width keyswitch) and includes a base plate <b>12</b>, the cap <b>14</b>, a lifting mechanism <b>16</b>, a returning device <b>18</b>, and at least one support mechanism <b>20</b> (two shown in <figref idref="DRAWINGS">FIG. 1</figref>, but not limited thereto). The cap <b>14</b> has a longitudinal axis L. The lifting mechanism <b>16</b> is disposed between the base plate <b>12</b> and the cap <b>14</b>. The cap <b>14</b> can move between a pressed position and a non-pressed position relative to the base plate <b>12</b> via the lifting mechanism <b>16</b>. The lifting mechanism <b>16</b> includes a first support plate <b>22</b> and a second support plate <b>24</b>. The first support plate <b>22</b> and the second support plate <b>24</b> are coupled to each other. The first support plate <b>22</b> has at least one first opening <b>26</b> (five shown in <figref idref="DRAWINGS">FIG. 1</figref>, but not limited thereto). The base plate <b>12</b> is partially disposed through the first opening <b>26</b> to make the first support plate <b>22</b> movably connected to the base plate <b>12</b>. The first support plate <b>22</b> has a first edge <b>28</b> and a second edge <b>30</b>. The first edge <b>28</b> abuts against the base plate <b>12</b> to make the first support plate <b>22</b> rotatable relative to the base plate <b>12</b> via the first edge <b>28</b>. The second edge <b>30</b> is opposite to the first edge <b>28</b> and abuts against the cap <b>14</b>. The first edge <b>28</b> and the second edge <b>30</b> are parallel to the longitudinal axis L to make the first support plate <b>22</b> strip-shaped. The second support plate <b>24</b> has at least one second opening <b>32</b> (two shown in <figref idref="DRAWINGS">FIG. 1</figref>, but not limited thereto). The base plate <b>12</b> is partially disposed through the second opening <b>32</b> to make the second support plate <b>24</b> movably connected to the base plate <b>12</b>. The second support plate <b>24</b> has a third edge <b>34</b> and a fourth edge <b>36</b>. The third edge <b>34</b> abuts against the base plate <b>12</b> to make the second support plate <b>24</b> rotatable relative to the base plate <b>12</b> via the third edge <b>34</b>. The fourth edge <b>36</b> is opposite to the third edge <b>34</b> and abuts against the cap <b>14</b>. The third edge <b>34</b> and the fourth edge <b>36</b> are parallel to the longitudinal axis L to make the second support plate <b>22</b> strip-shaped.

To be more specific, the first edge <b>28</b> could have a first middle section <b>38</b> and a first tail section <b>40</b>. The first middle section <b>38</b> is close to a center point C of the longitudinal axis L. The first tail section <b>40</b> is close to a terminal point P of the longitudinal axis L. The third edge <b>34</b> could have a second middle section <b>42</b> and a second tail section <b>44</b>. The second middle section <b>42</b> is close to the center point C of the longitudinal axis L. The second tail section <b>44</b> is close to the terminal point P of the longitudinal axis L. The first tail section <b>40</b> is away from the second tail section <b>44</b> forming a containing space <b>46</b>. The support mechanism <b>20</b> is disposed in the containing space <b>46</b>. In practical application, the first support plate <b>22</b> could further have a containing slot <b>48</b> and an auxiliary edge <b>50</b> corresponding to the support mechanism <b>20</b>. The support mechanism <b>20</b> is partially contained within the containing slot <b>48</b>. The auxiliary edge <b>50</b> extends outwardly from the containing slot <b>48</b> to be located at an outer side of the support mechanism <b>20</b> away from the returning device <b>18</b> and abuts against the base plate <b>12</b>. Accordingly, the first support plate <b>22</b> can rotate steadily relative to the base plate <b>12</b> via the first edge <b>28</b> and the auxiliary edge <b>50</b> to improve the tactile feedback of the keyswitch <b>10</b>.

The returning device <b>18</b> is located between the first support plate <b>22</b> and the second support plate <b>24</b> for providing a returning force to drive the cap <b>14</b> to move from the pressed position back to the non-pressed position with rotation of the first support plate <b>22</b> relative to the base plate <b>12</b> via the first edge <b>28</b> and rotation of the second support plate <b>24</b> relative to the base plate <b>12</b> via the third edge <b>34</b>. In this embodiment, the returning device <b>18</b> could preferably adopt the magnetic attraction design. For example, please refer to <figref idref="DRAWINGS">FIG. 1</figref>, <figref idref="DRAWINGS">FIG. 2</figref>, and <figref idref="DRAWINGS">FIG. 3</figref>. <figref idref="DRAWINGS">FIG. 2</figref> is a cross-sectional diagram of the keyswitch <b>10</b> in <figref idref="DRAWINGS">FIG. 1</figref> along a cross-sectional line A-A. <figref idref="DRAWINGS">FIG. 3</figref> is a cross-sectional diagram of the cap <b>14</b> in <figref idref="DRAWINGS">FIG. 2</figref> being pressed to the pressed position. As shown in <figref idref="DRAWINGS">FIG. 1</figref>, <figref idref="DRAWINGS">FIG. 2</figref>, and <figref idref="DRAWINGS">FIG. 3</figref>, the returning device <b>18</b> includes a first magnetic member <b>52</b> and a second magnetic member <b>54</b>. The first magnetic member <b>52</b> extends from the first edge <b>28</b> toward the second support plate <b>24</b>. The second magnetic member <b>54</b> is disposed on the base plate <b>12</b> corresponding to the first magnetic member <b>52</b>. Accordingly, the first magnetic member <b>52</b> can magnetically attract the second magnetic member <b>54</b> to generate the returning force. When the cap <b>14</b> is not pressed, the returning force keeps the cap <b>14</b> at the non-pressed position as shown in <figref idref="DRAWINGS">FIG. 2</figref>. When the cap <b>14</b> is pressed by an external force to make the first magnetic member <b>52</b> separate from the second magnetic member <b>54</b> with rotation of the first support plate <b>22</b> relative to the base plate <b>12</b> via the first edge <b>28</b>, the cap <b>14</b> moves from the non-pressed position as shown in <figref idref="DRAWINGS">FIG. 2</figref> to the pressed position as shown in <figref idref="DRAWINGS">FIG. 3</figref> with the lifting mechanism <b>16</b> performing the triggering operation to execute a corresponding input function. On the other hand, when the external force is released, the returning force makes the first magnetic member <b>52</b> return to be adjacent the second magnetic member <b>54</b>. Accordingly, the cap <b>14</b> could move from the pressed position as shown in <figref idref="DRAWINGS">FIG. 3</figref> back to the non-pressed position as shown in <figref idref="DRAWINGS">FIG. 2</figref> with the lifting mechanism <b>16</b>, so that the cap <b>14</b> could automatically return to its original position.

Please refer to <figref idref="DRAWINGS">FIGS. 1-4</figref>. <figref idref="DRAWINGS">FIG. 4</figref> is an enlarged diagram of the first support plate <b>22</b> and the second support plate <b>24</b> in <figref idref="DRAWINGS">FIG. 1</figref> from another viewing angle. As shown in <figref idref="DRAWINGS">FIGS. 1-4</figref>, the keyswitch <b>10</b> could further include a membrane circuit board <b>56</b>. The membrane circuit board <b>56</b> is disposed on the base plate <b>12</b> and has at least one first triggering switch <b>58</b> (one shown in <figref idref="DRAWINGS">FIG. 2</figref>, but not limited thereto) corresponding to the second edge <b>30</b> and at least one second triggering switch <b>60</b> (one shown in <figref idref="DRAWINGS">FIG. 2</figref>, but not limited thereto) corresponding to the fourth edge <b>36</b>. In practical application, for making the cap <b>14</b> capable of triggering the first triggering switch <b>58</b> and the second triggering switch <b>60</b> surely, the second edge <b>30</b> could have at least one first bending structure <b>62</b> (one shown in <figref idref="DRAWINGS">FIG. 4</figref>, but not limited thereto), and the fourth edge <b>36</b> could have at least one second bending structure <b>64</b> (one shown in <figref idref="DRAWINGS">FIG. 4</figref>, but not limited thereto). The first bending structure <b>62</b> has a first protruding portion <b>63</b> corresponding to the first triggering switch <b>58</b>, and the second bending structure <b>64</b> has a second protruding portion <b>65</b> corresponding to the second triggering switch <b>60</b>. In such a manner, when the cap <b>14</b> moves to the pressed position as shown in <figref idref="DRAWINGS">FIG. 3</figref> relative to the base plate <b>12</b> via the lifting mechanism <b>16</b>, the first protruding portion <b>63</b> presses the first triggering switch <b>58</b> and the second protruding portion <b>65</b> presses the second triggering switch <b>60</b> for triggering the membrane circuit board <b>56</b> to complete the triggering operation for executing a corresponding input function.

The support mechanism <b>20</b> is located between the first support plate <b>22</b> and the second support plate <b>24</b>. The support mechanism <b>20</b> could have a first support member <b>66</b> and a second support member <b>68</b>. The first support member <b>66</b> is movably connected to the cap <b>14</b> and the base plate <b>12</b>. The second support member <b>68</b> is movably connected to the cap <b>14</b> and the base plate <b>12</b> and is pivoted to the first support member <b>66</b>. To be more specific in this embodiment, the support mechanism <b>20</b> could preferably adopt a scissor support design, and the related description could be as shown in <figref idref="DRAWINGS">FIG. 1</figref> and <figref idref="DRAWINGS">FIG. 5</figref>. <figref idref="DRAWINGS">FIG. 5</figref> is an exploded diagram of the base plate <b>12</b>, the cap <b>14</b>, and the support mechanism <b>20</b> in <figref idref="DRAWINGS">FIG. 1</figref>, and the base plate <b>12</b> and the cap <b>14</b> are partially depicted in <figref idref="DRAWINGS">FIG. 5</figref>. As shown in <figref idref="DRAWINGS">FIG. 1</figref> and <figref idref="DRAWINGS">FIG. 5</figref>, the cap <b>14</b> could have a first sliding slot <b>70</b> and a first engaging slot <b>72</b>. The base plate <b>12</b> could have a second sliding slot <b>74</b> and a second engaging slot <b>76</b>. The first support member <b>66</b> could have a first sliding portion <b>78</b> and a first pivot portion <b>80</b>. The first sliding portion <b>78</b> is slidably disposed in the first sliding slot <b>70</b>, and the first pivot portion <b>80</b> is rotatably connected to the second engaging slot <b>76</b>. The second support member <b>68</b> could have a second sliding portion <b>82</b> and a second pivot portion <b>84</b>. The second sliding portion <b>82</b> is slidably disposed in the second sliding slot <b>74</b>, and the second pivot portion <b>84</b> is rotatably connected to the first engaging slot <b>72</b>. In such a manner, during the cap <b>14</b> moves between the non-pressed position and the pressed position as shown in <figref idref="DRAWINGS">FIG. 3</figref>, the aforesaid connection design could generate the effect that a edge of the cap <b>14</b> close to the terminal point P of the longitudinal axis L could move together with a center portion of the cap <b>14</b> close to the center point C via the first support member <b>66</b> and the second support member <b>68</b>. Furthermore, the aforesaid connection design could also increase the pull-out force of the cap <b>14</b> via connection of the first sliding portion <b>78</b> and the first sliding slot <b>70</b> and connection of the second pivot portion <b>84</b> and the first engaging slot <b>72</b> to efficiently solve the prior art problem that the cap of the conventional multiple-width keyswitch could fall off easily.

In practical application, the keyswitch <b>10</b> could further adopt an auxiliary support to improve the motion steadiness of the cap <b>14</b>. For example, please refer to <figref idref="DRAWINGS">FIG. 1</figref> and <figref idref="DRAWINGS">FIG. 6</figref>. <figref idref="DRAWINGS">FIG. 6</figref> is a partial enlarged exploded diagram of the keyswitch <b>10</b> in <figref idref="DRAWINGS">FIG. 1</figref>. As shown in <figref idref="DRAWINGS">FIG. 1</figref> and <figref idref="DRAWINGS">FIG. 6</figref>, the keyswitch <b>10</b> could further include at least one auxiliary support <b>86</b> (two shown in <figref idref="DRAWINGS">FIG. 1</figref>, but not limited thereto). The auxiliary support <b>86</b> is disposed between the cap <b>14</b> and the base plate <b>12</b> and is alternately arranged with the support mechanism <b>20</b>. The auxiliary support <b>86</b> could have a third engaging structure <b>88</b> corresponding to the base plate <b>12</b>, and the base plate <b>12</b> could have a fourth engaging structure <b>90</b> corresponding to the third engaging structure <b>88</b>. The third engaging structure <b>88</b> is engaged with the fourth engaging structure <b>90</b> (e.g. via the structural engagement design of the sliding portion (could be regarded as the third engaging structure <b>88</b>) and the sliding slot (could be regarded as the fourth engaging structure <b>90</b>) as shown in <figref idref="DRAWINGS">FIG. 6</figref>, but not limited thereto), to make the auxiliary support <b>86</b> movably connected to the base plate <b>12</b>. Furthermore, the auxiliary support <b>86</b> could have a fifth engaging structure <b>92</b> corresponding to the cap <b>14</b> and the cap <b>14</b> could have a sixth engaging structure <b>94</b> corresponding to the fifth engaging structure <b>92</b>. The fifth engaging structure <b>92</b> is engaged with the sixth engaging structure <b>94</b> (e.g. via the structural engagement design of the pivot portion (could be regarded as the fifth engaging structure <b>92</b>) and the engaging slot (could be regarded as the sixth engaging structure <b>94</b>) as shown in <figref idref="DRAWINGS">FIG. 6</figref>, but not limited thereto), to make the auxiliary support <b>86</b> movably connected to the cap <b>14</b>.

It should be mentioned that the cap returning design adopted by the present invention is not limited to the aforesaid embodiment, meaning that the present invention could utilize a resilient member (e.g. rubber dome or spring) to provide the returning force in another embodiment. For example, please refer to <figref idref="DRAWINGS">FIG. 7</figref> and <figref idref="DRAWINGS">FIG. 8</figref>. <figref idref="DRAWINGS">FIG. 7</figref> is a diagram of a keyswitch <b>10</b>′ according to another embodiment of the present invention. <figref idref="DRAWINGS">FIG. 8</figref> is a cross-sectional diagram of the keyswitch <b>10</b>′ in <figref idref="DRAWINGS">FIG. 7</figref> along a cross-sectional line B-B when the cap <b>14</b> is pressed. For clearly showing the internal mechanical design of the keyswitch <b>10</b>′, the cap <b>14</b> is briefly depicted by dotted lines in <figref idref="DRAWINGS">FIG. 7</figref>. Components both mentioned in this embodiment and the aforesaid embodiment represent components with similar structures or functions, and the related description is omitted herein. As shown in <figref idref="DRAWINGS">FIG. 7</figref> and <figref idref="DRAWINGS">FIG. 8</figref>, the keyswitch <b>10</b>′ includes a returning device <b>18</b>′, the base plate <b>12</b>, the cap <b>14</b>, the lifting mechanism <b>16</b>, at least one support mechanism <b>20</b> (two shown in <figref idref="DRAWINGS">FIG. 7</figref>, but not limited thereto), and a membrane circuit board <b>56</b>. In this embodiment, the returning device <b>18</b>′ could include a resilient body <b>96</b>. The resilient body <b>96</b> could abut against the cap <b>14</b> and the base plate <b>12</b> respectively. Accordingly, when the external force is released, the compressed resilient body <b>96</b> pressed by the cap <b>14</b> (as shown in <figref idref="DRAWINGS">FIG. 8</figref>) could provide the returning force to the cap <b>14</b>, to make the cap move from a pressed position as shown in <figref idref="DRAWINGS">FIG. 8</figref> back to a non-pressed position as shown in <figref idref="DRAWINGS">FIG. 7</figref> with the lifting mechanism <b>16</b>, for generating the automatic cap returning effect.

Furthermore, please refer to <figref idref="DRAWINGS">FIG. 9</figref>, which is an assembly diagram of a cap <b>14</b>′, the first support plate <b>22</b> and the second support plate <b>24</b> according to another embodiment of the present invention. Components both mentioned in this embodiment and the aforesaid embodiment represent components with similar structures or functions, and the related description is omitted herein. As shown in <figref idref="DRAWINGS">FIG. 9</figref>, at least one first engaging structure <b>98</b> (two shown in <figref idref="DRAWINGS">FIG. 9</figref>, but not limited thereto) is formed on the cap <b>14</b>′, and the first support plate <b>22</b> has a second engaging structure <b>99</b> corresponding to the first engaging structure <b>98</b>. To be more specific, in this embodiment, the first engaging structure <b>99</b> could preferably be a hook extending from the cap <b>14</b> toward the first support plate <b>22</b>, and the second engaging structure <b>99</b> could correspondingly be an engaging hole formed on the first support plate <b>22</b>. The first engaging structure <b>98</b> (i.e. the hook) is engaged with the second engaging structure <b>99</b> (i.e. the engaging hole) to constrain the deformation movement of the cap <b>14</b>′ relative to the first support plate <b>22</b>, for preventing the cap <b>14</b>′ from being bulged due to uneven pressing force or stress concentration during the cap <b>14</b> is pressed. To be noted, the aforesaid design could also be applied to the second support plate <b>24</b> (as shown in <figref idref="DRAWINGS">FIG. 9</figref>), and the related description could be reasoned from analogy. Moreover, the present invention could prevent deformation of the cap via structural engagement of the cap and the base plate in another embodiment. That is to say, in another embodiment, a first engaging structure (e.g. the hook as shown in <figref idref="DRAWINGS">FIG. 9</figref>) could be formed on the cap, and the base plate could have a second engaging structure (e.g. the engaging hole as shown in <figref idref="DRAWINGS">FIG. 9</figref>) corresponding to the first engaging structure. Accordingly, the first engaging structure could be engaged with the second engaging structure for preventing deformation of the cap. As for related description for other derived embodiments (e.g. the first support plate has a hook formed thereon to be engaged with an engaging hole on the cap), it could be reasoned from analogy according to the aforesaid embodiments and omitted herein.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.